JPH113550A - Information recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To record, erase and reproduce information with light beams having proper power to/from respective recording layers of a multilayered recording medium by selecting conditions of the recording, the erasing and the reproduction to information tracks on the respective recording layers by a trail writing means and performing the recording, the erasing and the reproduction to/from the information track on an arbitrary recording layer based on the conditions. SOLUTION: A control part 6 calculates a layer number and a radial position on which light beams are radiated based on address information and reads out the power value of light beams prelimiarily stored in an EP-ROM 7 according to the calculation to instruct it to an LD power control part 16. As a result, light beams having a proper power in accordance with the recording layer and the radial position of a recording medium 1 can be outputted. Moreover, this power control part 16 changes over the power of the light beam to a proper value in operations of the recording, the erasing and the reproduction. Further, the control part 6 performs a trial writing operation on an information track at the prescribed recording layer and the prescribed radial position of the medium 1 as necessary to select optimum conditions of the recording, the erasing and the reproduction based on the inspection of the reproduced signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording / reproducing apparatus for recording / reproducing information on / from an information recording medium such as a magneto-optical disk or an optical disk, and more particularly to recording / reproducing on / from a multilayer recording medium having a plurality of recording layers. The present invention relates to an information recording / reproducing device.

[0002]

2. Description of the Related Art In recent years, various attempts have been made to improve the storage capacity of information recording media such as magneto-optical disks. In particular, as a technique for increasing the data density of a recording medium, it has been considered to increase the number of recording layers.

Generally, in a recording medium used for a magneto-optical recording / reproducing method or a phase change recording method, a temperature of a part of a recording layer is reduced by irradiating a light beam having a diameter as small as about 1 micron during recording. It is done by raising. In a recording medium that performs recording using heat called heat mode recording, the power of the irradiating light beam is appropriately set when recording a mark representing information in order to reproduce information exactly as recorded. It is necessary to.

For this reason, some information recording / reproducing apparatuses have a power value suitable for such recording as a recording power table. Further, there is an operation of actually recording on a recording medium and creating the above-mentioned power table. At the time of recording, the recording power is set based on this table.

[0005] The power suitable for this recording varies depending on the linear velocity of the recording medium at the time of recording. In particular, in applications requiring high-speed data access, the recording medium is often used at a constant rotation speed regardless of the radial position of recording / reproduction.

However, in this case, the linear velocity of the recording medium varies depending on the radial position of the recording medium, and the power suitable for recording also varies at the radial position. For this reason, the recording medium is divided into a plurality of areas at radial positions, the recording power for each area is provided in the recording power table, and the recording power is set for each zone based on this table. Have been.

[0007] Further, since the value of the power suitable for this recording generally differs for each recording medium, a method of measuring information on the recording power at the time of production of the recording medium and recording it in advance on the recording medium is adopted. . Furthermore, actual recording is performed to determine recording conditions specific to the recording medium,
This information is read when the recording medium is inserted into the device,
Rewrite the value of the above power table based on that value,
Some devices have been devised so that recording can be performed with appropriate power according to the recording medium.

[0008]

In such a conventional information recording / reproducing apparatus, however, power control is performed based on a single layer, that is, a power table for a single recording layer. There was a problem that an appropriate power could not be set. In general, a multilayer recording medium has a structure in which a number of disks each having a recording film, a dielectric film, or a transparent film formed thereon are adhered to each other during the production of the recording medium. Is a factor that creates a lot of differences.

An object of the present invention is to solve such a problem. An information recording apparatus capable of recording, reproducing, or erasing information on each recording layer of a multi-layer recording medium having a plurality of recording layers with a light beam having an appropriate power. It is intended to provide a playback device.

[0010]

In order to achieve the above object, an information recording / reproducing apparatus according to the present invention records a plurality of predetermined information on an information track on an arbitrary recording layer on a trial basis under different recording conditions. Test recording means, reproduction signal detection means for detecting a reproduction signal indicating predetermined information reproduced from an information track on an arbitrary recording layer, and test recording means for each of the information tracks on the predetermined recording layer. Trial writing means for recording a plurality of information, detecting reproduction signals indicating the predetermined information by reproduction signal detection means, and selecting recording, erasing or reproduction conditions for the information track based on the reproduction signals, The recording, erasing or reproducing conditions for the information track on each recording layer are selected by the writing means, and the selected recording, erasing or reproducing conditions are selected. In which a control means for performing recording of information to the information track on any recording layer, erase or reproduce Zui.

Therefore, as test writing, a plurality of pieces of predetermined information are experimentally recorded on information tracks on a predetermined recording layer by test recording under different recording conditions, and reproduced from the information tracks on the recording layer. The reproduction signal indicating the predetermined information is detected by the signal detection means. Then, by this test writing, recording, erasing or reproducing conditions for the information track on each recording layer are selected, and information of an information track on an arbitrary recording layer is selected based on the selected recording, erasing or reproducing condition. Recording, erasing or reproduction is performed.

Further, the control means is provided by a trial writing means,
A recording, erasing or reproducing condition for a plurality of information tracks having different radial positions on a predetermined recording layer is selected, and an information track at an arbitrary radial position on the recording layer is selected based on the selected recording, erasing or reproducing condition. The recording, erasing or reproducing conditions are calculated. Therefore, recording, erasing or reproducing conditions for a plurality of information tracks having different radial positions on a predetermined recording layer are selected, and information on an arbitrary radial position on the recording layer is determined based on the selected recording, erasing or reproducing condition. Recording, erasing or reproducing conditions for the track are calculated.

[0013] Further, the control means includes a trial writing means,
Recording, erasing or reproducing conditions for information tracks at the same radial position on two different recording layers are respectively selected, and one of the recordings is determined based on the sensitivity coefficient between the two recording layers obtained from the selected recording, erasing or reproducing conditions. The recording, erasing or reproducing condition for the information track at each radial position on the other recording layer is calculated from the recording, erasing or reproducing condition for the information track at each radial position on the layer. Therefore, recording, erasing or reproducing conditions for information tracks at the same radial position on two different recording layers are respectively selected, and one of the recording and erasing or reproducing conditions is determined based on the sensitivity coefficient between the two recording layers obtained from the selected recording, erasing or reproducing conditions. The recording, erasing or reproducing condition for the information track at each radial position on the other recording layer is calculated from the recording, erasing or reproducing condition for the information track at each radial position on the recording layer.

Further, as a recording condition, a peak value and a pulse width of a recording pulse are used. Further, the reproducing power level and the frequency of the high frequency superposition are used as the reproducing conditions. Further, the erasing power level is used as the erasing condition.

[0015]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an information recording / reproducing apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 2 denotes an optical head arranged so as to be movable in a radial direction of the recording medium 1.

The optical head 2 is a light emitting element (semiconductor laser: LD) 2 for outputting a light beam (laser light) having a predetermined power.
1. a light receiving element (PIN photodiode) 24 for detecting light reflected on the recording medium 1, a light receiving element (PIN photodiode) 27 for detecting the output of the light emitting element 21, a focus actuator 25 for controlling the focus of the light beam,
And a track actuator 26 for controlling the track position.

The recording medium 1 has a plurality of recording layers, here 2
The recording layers 1A to 1C are formed so as to overlap in the thickness direction. Each of the recording layers 1 </ b> A to 1 </ b> C has concentric or spiral track grooves formed with lands and grooves alternately in the radial direction of the recording medium 1.

The control section 6 is a CPU (control means) for controlling each section of the information recording / reproducing apparatus, and has various arithmetic processing functions. The EP-ROM 7 is a non-volatile memory, and stores information necessary for the control operation of the control unit 6.

In particular, the EP-ROM 7 stores information indicating the optimum power of the light beam used in the recording, erasing or reproducing operation. This information is called a power map. In the present invention, the optimum power of the light beam used at the time of recording, erasing or reproducing operation is determined for each recording layer of the recording medium 1 in correspondence with the information track at each radial position. The information shown is stored.

The light beam emitted from the light emitting element 21 of the optical head 2 to the recording medium 1 via the spectroscope (polarizing beam splitter) 22 forms a light beam spot on a land or groove on a predetermined recording layer. The reflected light is received by the light receiving element 24 whose light receiving unit is divided into a plurality (for example, four) through the spectroscope 22, and the respective light receiving signals are output to the signal generating unit 3.

The signal generating section 3 generates various servo signals such as a tracking error signal TE indicating a positional error between the light beam and the track and a focus error signal FE indicating a focus error based on these light receiving signals. Further, the signal generation unit 3 generates a reproduction signal RD indicating information recorded on the track.

The focus error signal FE is a signal having a shape called an S-shaped curve, and the tracking error signal T
E is a sinusoidal signal corresponding to one pitch of the track. Note that the tracking error signal TE is detected as a difference between the light receiving signals of the respective divided light receiving units.

On the other hand, the tracking error signal is the sum of the respective light receiving signals, and the phase is shifted by 90 ° from the tracking error signal TE. Further, the reproduction signal RD includes a signal obtained from a preformat section of the recording medium 1 and a signal obtained from a data section written by a user.

The ID detecting section 5 recognizes the ID address written in the preformat section of the recording medium 1 from the reproduced signal RD. The ID address includes a layer number, a track number, a sector number, and the like, whereby the control unit 6 is notified of the laser spot follow-up position on the recording medium 1.

Depending on the format of the recording medium 1, there may be a case where the layer number is not directly written (for example, a case where a track number, a sector number, etc. are assigned sequentially over each recording layer). However, by recognizing which recording layer of the recording medium 1 the laser spot follows, based on the ID address and the format, the layer number can be obtained.

The position of the objective lens 23 constituting the focusing moving means together with the focus actuator 25 in the medium vertical (thickness) direction is detected by an objective lens focus position sensor 28 and output as an objective lens focus position signal LP. This signal LP is
As the objective lens 23 moves, it monotonically increases or decreases.

The objective lens focus position sensor 28
Low detection sensitivity and wide detection range compared to focus error detection. The objective lens focus position signal LP output from the sensor 28 has a full scale corresponding to the objective lens 2.
3 is a sensor signal having a control gradient corresponding to an operation range width of 1 to 2 mm.

On the other hand, the position of the objective lens 23 in the medium radial direction is detected by an objective lens track position sensor 29, and an objective lens track position signal TP is output. This signal TP monotonically increases or decreases as the objective lens 23 moves.

The reproduction signal RD, the focus error signal FE, the tracking error signal TE and the objective lens focus position signal LP are detected by the A / D converter 4 and sent to the control unit 6 for controlling the entire apparatus. Output as digital information. This allows
The control unit 6 selects the optimum recording / erasing power of the light beam in the track at each radial position on each recording layer,
Alternatively, gain adjustment and offset adjustment of each servo loop are performed.

Next, the focus servo loop among the servo loops will be described. The focus servo loop for seeking and illuminating the light beam spot on a predetermined recording layer of the recording medium 1 includes a gain setting unit 8A and a phase compensating unit 10A.
A, a switch 12A of the seek / following switching unit 12, an AF driver 13, and a focus actuator 25.

The focus error signal FE is set to an optimum gain by the gain setting section 8A and the phase compensation section 10A. The offset applying unit 12 performs a tracking control operation (focusing operation) for causing a laser spot to follow a target recording layer of the recording medium 1.
An offset value is applied to the focus error signal FE output from 0A to change the control target value.

Further, in order to perform an interlayer seek operation for moving a laser spot to a desired recording layer, an offset value is applied to the objective lens focus position signal LP to change a control target value. Note that the focus error signal FE
The resolution of the offset value applied to the objective lens focus position signal LP may be a voltage step at which the moving amount of the objective lens 23 is about 0.01 μm and about 1 μm, respectively.

These signals to which the offset value is applied are:
The signal is input to a switch (SW) 12A of the seek / following switching unit 12. Switch 12A of seek / follow switching unit 12
Switches between the interlayer seek operation and the follow-up control operation by switching the signal of each servo loop in response to an instruction from the control unit 6.

In this case, the lens focus position signal LP is selected by the switch 12A during the interlayer seek operation, and the focus error signal FE is selected during the follow-up operation, and is output to the AF driver 13. As a result, a drive current is supplied from the AF driver 13 to the focus actuator 25, and the objective lens 23 is driven in a direction perpendicular to the medium, and the light beam spot is subjected to interlayer seek to a desired recording layer or tracking control.

A sweep unit 13 for sweeping the objective lens 23 in a direction perpendicular to the medium is provided before the AF driver 13.
A and a switch (SW) 13B for switching and connecting the A. Thus, focus pull-in is performed at the time of starting the apparatus.

Next, the tracking servo loop will be described. A tracking servo loop for seeking and following a light beam spot on a predetermined track of the recording medium 1 includes a gain setting unit 8B, a phase compensation unit 10B, a switch 12B of a seek / following switching unit 12, an AT driver 14, and a tracking actuator 26. ing.

The track error signal TE is set to an optimum gain by the gain setting section 8B and the phase compensation section 10B. The offset applying unit 12 performs a tracking control operation (tracking operation) for causing a laser spot to follow a target recording layer of the recording medium 1, and thus performs a phase compensating unit 10 </ b> A.
The target value of control is changed by applying an offset value to the track error signal TE output from the controller.

The resolution of the offset value applied to the track error signal TE may be a voltage step at which the moving amount of the objective lens 23 becomes about 0.01 μm. The signal TE to which the offset value is applied and the objective lens track position signal TP from the objective lens track position sensor 29 are input to the switch 12B of the seek / following switching unit 12.

Switch 12B of seek / following switching unit 12
Switches between the in-plane seek operation and the tracking control operation by switching the signal of each servo loop in response to an instruction from the control unit 6. In this case, the objective lens track position signal TP is selected by the switch 12A during the in-plane seek operation.

In the following operation, the track error signal T
E is selected and output to the AT driver 14 respectively. As a result, a drive current is supplied from the AT driver 14 to the tracking actuator 26, the objective lens 23 is driven in the radial direction of the medium, and the light beam spot is subjected to in-plane seek to a desired track or tracking control.

Next, the carriage servo loop will be described. A carriage servo loop for controlling the carriage for positioning the optical head 2 in the medium radial direction includes a gain setting unit 8C, a phase compensation unit 10C, an in-plane / interlayer seek switching unit 19, a reference speed unit 18, and a seek / following switching unit 12. It comprises a switch 12C and a carriage driver 15.

The objective lens track position signal TP output from the objective lens track position sensor 29 is set to an optimum gain by the gain setting section 8C and the phase compensation section 10C. The signal TP from the phase compensating unit 10C and the control signal from the in-plane / interlayer seek switching unit 19 are input to the switch 12C of the seek / following switching unit 12.

Switch 12C of seek / following switching unit 12
Switches the signal of each servo loop according to an instruction from the control unit 6. Thus, the in-plane / inter-layer seek operation for simultaneously performing the in-plane / inter-layer seek and the objective lens 2
3 is switched to a so-called double servo control operation in which the position in the medium radial direction is fed back to the carriage driver 15.

In this case, during the in-plane / interlayer seek operation,
The control signal from the in-plane / interlayer seek switching section 19 is selected by the switch 12A. At the time of the double servo control operation, the objective lens track position signal TP from the phase compensator 10C is selected, and the carriage driver 15
Output to

As a result, a drive current is supplied from the carriage driver 15 to the carriage (not shown), and the objective lens 23 of the optical head 2 is driven in the radial direction of the medium.
Then, the light beam spot is subjected to in-plane seek on a desired track, or tracking control is performed.

The in-plane / inter-layer seek switching section 19 detects the speed of the carriage based on the back electromotive voltage generated at the output of the carriage driver 15 in accordance with the movement of the carriage when performing the inter-layer seek and the in-plane seek simultaneously. I do. Then, a difference between the reference speed and the carriage speed output from the reference speed generating unit 18 is output to the seek / following switching unit 12 as a control signal.

At this time, the control unit 6 determines the moving speed of the carriage from the previously calculated moving amount in the radial direction of the medium, and causes the reference speed unit 27 to output a reference speed signal indicating the moving speed. Thus, control is performed so that the carriage moves at a desired speed. Further, the in-plane / interlayer seek switching section 19 always obtains the position of the carriage by always integrating the back electromotive voltage generated in the output of the carriage driver 15.

The control unit 6 estimates the current position in the medium radial direction based on the position information obtained by the in-plane / interlayer seek switching unit 19, and sequentially calculates the reference speed from the reference speed generation unit 18 accordingly. Change (for example, decelerate when approaching the target position). As described above, the interlayer seek for moving the laser spot in the medium perpendicular direction and the in-plane seek for moving the laser spot in the medium radial direction are performed simultaneously.

Thus, a drive current is supplied from the carriage driver 15 to a carriage (not shown) for positioning the optical head 2 in the medium radial direction, and the carriage is driven in the medium radial direction. As described above, the objective lens 23,
The tracking actuator 26 and the carriage
Functions as tracking movement means.

In this manner, the light beam spot is sought to a desired track on a desired recording layer of the recording medium 1 and controlled to follow, and a light beam having an optimum power is output at the spot position. 16 is an instruction from the control unit 6,
Alternatively, an LD power control unit that controls the LD driver 17 based on an LD power monitor signal from the light receiving element 27 that detects the output of the light emitting element 21 to output a light beam having a desired power from the light emitting element 21.

The control section 6 calculates the layer number and the radial position to which the light beam is radiated based on the above-mentioned address information, and stores the light stored in the EP-ROM 14 in advance according to the layer number and the radial position. The power value of the beam is read out and instructed to the LD power control unit 15. Thereby, a light beam having an appropriate power according to the recording layer and the radial position of the recording medium 1 is output.

The power control can be switched to an appropriate value by recording / erasing / reproducing operations.
Further, when the recording medium 1 is loaded, or as necessary, the control unit 6 performs a test writing operation on the information track on a predetermined recording layer and a predetermined radial position of the recording medium 1, and inspects a reproduction signal thereof. Thereby, the optimum recording, erasing or reproducing condition for the recording operation at each recording layer and the radial position is selected (test writing means).

Hereinafter, with reference to FIG. 2, an operation of selecting an optimum recording power for a multilayer non-overwrite recording medium will be described as an operation according to the first embodiment of the present invention. FIG. 2 is a flowchart showing an optimum recording power selection operation (test writing operation) for a multilayer non-overwrite recording medium.

Note that a non-overwrite recording medium is a recording medium in which the power of a light beam required for a recording operation is lower than the power of an erasing operation. Here, among the non-overwrite recording media, a multilayer recording medium having a plurality of recording layers formed thereon will be described as an example.

After the recording medium 1 reaches a predetermined number of revolutions after the recording medium 1 has been loaded into the information recording / reproducing apparatus, the optical head 2 is moved to the initial stage of the servo start-up by a predetermined seek control system (not shown). It is moved to the position (step 201).
Subsequently, a reference layer serving as a reference for the light beam power, for example,
The light beam spot follows a predetermined track on the recording layer closest to the optical head 2 or on the recording layer farthest from the optical head 2 (step 202).

In this case, adjustment of each servo loop, that is, servo adjustment may be performed. For example, the gain adjustment and offset adjustment of the focus servo loop and the gain adjustment and offset adjustment of the tracking servo loop are performed by the gain setting units 8A to 8C and the offset application unit 1.
Perform in step 1.

Thereafter, a test writing operation is performed on the track on the reference layer (steps 203 to 208). It is assumed that the test writing area has at least two or more points in the radial direction of the medium, in this case, radial positions R1 to Rm.

First, address information (formatted ID) of a sector recorded in the reference layer of the recording medium 1 in advance is used.
Information). As a result, after determining the current track position, the light beam spot is moved by the in-plane seek control system to the predetermined radial position Ri where the test writing is performed (step 203).

Here, by performing the above-described focus control and tracking control in parallel, the light beam spot follows a predetermined track, the address information is reproduced in the same manner as described above, and the current track is moved to the radial position Ri.
Make sure that Thereafter, an erase operation is performed on the predetermined track (step 204). However, if the recording medium 1 is a write-once (write-once) recording medium,
This erasing operation becomes unnecessary.

Next, as shown in FIG. 9, the recording power 81 of the light beam is switched stepwise to P1 to Pn, and the minimum mark is written continuously (step 205). FIG. 9 is a sequence diagram showing an operation for obtaining the optimum recording power of the non-overwrite recording medium.

The recording power waveform is based on a rectangular pulse as shown in FIG. FIG. 5 is an explanatory diagram showing one waveform example of the recording power of the light beam. However, an analog correction that emphasizes the rising characteristics (not shown)
May be.

When a mark written by changing the recording power in this way is reproduced, the reproduced signal level 8
2, and the reproduction signal amplitude level 83 is changed. As shown in FIG. 7, generally, an optimally recorded mark 62
, The reproduction signal amplitude 64 of the mark 61 recorded with excessive power decreases, and the level 67 of the average value decreases.
Rises. FIG. 7 is an explanatory diagram showing the relationship between the recording power of the light beam and the reproduction signal.

The mark 6 recorded with a small power
3, the reproduction signal amplitude 66 decreases, and the average level 69 also decreases. Therefore, when estimating the optimum recording power, the amplitude of the reproduction signal is monitored, and as shown in FIG. 9, the recording power having the maximum reproduction signal amplitude 83 is selected (step 206).

Subsequently, the optimum recording power is set as the optimum recording power Pw0i at the radial position Ri on the reference layer as EP-
It is stored in the ROM 7 (step 207). Note that the amplitude of the reproduction power may be observed each time the power is switched, or the maximum amplitude may be detected collectively after writing first with the continuously switched power.

In this manner, the processing of steps 203 to 207 (test writing means) is repeatedly performed for the radial positions R1 to Rm (step 20).
8) Obtain the optimum power of the track at each of the radial positions R1 to Rm on the reference layer. Next, a test writing operation is performed on a recording layer other than the reference layer formed on the recording medium 1 (steps 209 to 218).

In this case, only one of the radial positions R1 to Rm is selected as the track on which the test writing is performed.
Incidentally, by selecting the final trial writing radius position Rm of the land track as the radius position, the movement control of the optical head 2 can be omitted, and the processing time can be shortened.

First, an interlayer seek is performed on a recording layer on which test writing has not been performed, for example, the j-th layer (step 209), and the light beam spot follows the track at the radial position Rm (step 210). Thereafter, steps 203 to 20 described above are performed.
7 (trial writing means), the radial position Rm on the j-th layer
The recording is performed by changing the recording power step by step, and the maximum amplitude of the reproduced signal is detected.

Then, the recording power is stored as the optimum recording power Pwjm of the track at the radial position Rm on the j-th layer (steps 211 to 214: trial writing means). Next, the optimum recording power Pw at the radial position Rm of the j-th layer
jm and the optimum recording power Pw at the radial position Rm of the reference layer.
0m, the sensitivity coefficient αj of the optimum recording power between both recording layers is calculated by the following equation (step 21).
5).

Αj = Pwjm / Pw0m If this sensitivity coefficient αj is used, the optimum recording power can be calculated for each arbitrary radial position on the j-th layer (step 21).
6). That is, the above-described sensitivity coefficient αj is integrated with the optimum recording power Pw0i detected at each radial position of the reference layer, and
The optimum recording power Pwji at each radial position of the j-th layer is calculated.

The optimum recording power at successive radial positions in the same recording layer is created by interpolation based on the optimum recording power obtained at each radial position by trial writing.
The obtained optimum recording power for each radial position of the j-th layer is stored in the EP-ROM 7 or the like as a power map (step 217).

By repeating the processing of steps 209 to 217 for each recording layer in this way (step 218), the optimum recording power of the track at each radial position on all the recording layers of the recording medium 1 can be reduced. Get the power map shown. Then, the recording power of the light beam in the subsequent operation is controlled based on the power map.

Next, referring to FIGS. 3 and 4, the second embodiment of the present invention will be described.
As an operation according to the embodiment, an operation of selecting an optimum recording power for a multilayer overwrite recording medium will be described. FIGS. 3 and 4 are flowcharts showing the optimum recording power selection operation (test writing operation) for the overwrite recording medium.

Note that an overwrite recording medium is a recording medium such as a magneto-optical recording medium or a phase-change recording medium in which the power of a light beam required for a recording operation is higher than the power of an erasing operation. That means. Here, among the overwrite recording media, a multilayer recording medium having a plurality of recording layers formed will be described as an example.

After the recording medium 1 reaches a predetermined number of revolutions after the recording medium 1 is loaded in the information recording / reproducing apparatus, the optical head 2 is servo-started by a predetermined seek control system (not shown). (Step 301). Subsequently, the light beam spot is made to follow a predetermined track on a reference layer serving as a reference of the light beam power, for example, a recording layer closest to the optical head 2 or a recording layer farthest from the optical head 2 (step 302).

In this case, adjustment of each servo loop, that is, servo adjustment may be performed. For example, the gain adjustment and offset adjustment of the focus servo loop and the gain adjustment and offset adjustment of the tracking servo loop are performed by the gain setting units 8A to 8C and the offset application unit 1.
Perform in step 1.

Thereafter, a test writing operation is performed on the track on the reference layer (steps 303 to 306). It is assumed that the test writing area has at least two or more points in the radial direction of the medium, in this case, radial positions R1 to Rm.

First, the address information (formatted ID information) of the sector recorded in advance on the recording medium 1 is reproduced. Thus, after determining the current track position, the optical head 2 is moved by the seek control system to a predetermined test writing area (step 303).

Here, by performing the above-described focus control and tracking control in parallel, the light beam spot follows the predetermined track, the address information is reproduced in the same manner as described above, and the current track is moved to the radial position Ri.
Make sure that Thereafter, a test writing process is performed on a predetermined radius position of a predetermined recording layer that is currently being tracked (step 304).

FIG. 4 is a flowchart showing a test writing process for an overwrite recording medium.
This will be described with reference to FIG. First, a DC (direct current) recording and a DC (direct current) erasing operation are performed on the track at the radial position where the tracking operation is currently performed, and the maximum value (recording state) L of the reproduced signal is obtained.
w and the minimum value (erased state) Le are obtained (step 4).
01).

Next, as shown in FIG. 10, the recording power 91 of the light beam is switched step by step from P1 to Pn, and the long mark is written continuously (step 402). FIG. 10 is a sequence diagram showing an operation for obtaining the optimum recording power of the overwrite recording medium. The recording power waveform is based on a pulse train as shown in FIG. FIG. 6 is an explanatory diagram showing another waveform example of the recording power of the light beam.

When a long mark written by changing the recording power 91 in this way is reproduced, the DC (direct current) component of the reproduced signal level 92 is changed. When the change exceeds 10% (DLew) of the width of Lw-Le, the recording power 91 is stored in the EP-ROM 7 as Phth (steps 403 and 404).

Next, as shown in FIG. 11, a long mark is recorded by a recording pulse set using the obtained recording power Phth (step 405). FIG. 11 is a sequence diagram showing an operation for obtaining the optimum erasing power of the overwrite recording medium. Thereafter, the erasing power 10 is gradually increased.
1 is switched to perform erasure (step 406).

The reproduced signal level 102 after erasure is Lw-L
The erasing power 101 in the case where the width is less than 10% of the width of e (DLew) is stored as Plth in the EP-ROM 7 (steps 407 and 408). And the obtained Pht
The erase power Pa is calculated using h and Plth (step 409).

Next, P is calculated using the obtained erasing power Pa.
The minimum mark is repeatedly recorded while changing w1 stepwise. Thereafter, the average value level of the minimum mark repetition reproduction signal is detected, and the recording power Pw1 whose level is at the center of the width of Lw-Le is selected.

Further, a long mark is repeatedly recorded using Pa and Pw1. Then, as shown in FIG. 8, the recording power Pw2 at which the average value level of the long mark repetition reproduction signal becomes the median of the width of Lw-Le is selected (steps 410 and 411). FIG. 8 is an explanatory diagram showing the relationship between the optimum recording power and the reproduction signal level.

As a result, the optimum recording and erasing powers Pa, Pw1 and Pw2 are obtained at predetermined radial positions on the predetermined recording layer during the following operation, and the process is terminated (step 412). In this manner, the powers Pa, Pw1, and Pw2 obtained in the test writing process (test writing means) in step 304 (see FIG. 3) are set as the optimum powers at the radial position Ri of the reference layer that is currently following up as EP. -RO
It is stored in M7 (step 305).

By repeating the processing of steps 303 to 307 for the radial positions R1 to Rm in this manner (step 316), it is possible to optimally record tracks at the respective radial positions R1 to Rm on the reference layer. Get erase power. Next, a test writing operation is performed on a recording layer other than the reference layer formed on the recording medium 1 (step 3).
07-313).

In this case, only one of the radial positions R1 to Rm is selected as the track on which the test writing is performed.
Incidentally, by selecting the final trial writing radius position Rm of the land track as the radius position, the movement control of the optical head 2 can be omitted, and the processing time can be shortened.

First, interlayer seek is performed on a recording layer on which test writing has not been performed, for example, the j-th layer (step 307). Subsequently, the light beam spot follows the track at the radial position Rm (step 308).

Thereafter, the test writing process shown in FIG. 4 is executed in the same manner as in step 304 described above, so that the optimum recording and erasing powers Pa, Pw1, and Pw2 of the track at the radial position Rm on the j-th layer are obtained. Is obtained (step 309).
Then, it is stored in the EP-ROM 7 (step 31).
0).

Subsequently, based on the optimum power at the radial position Rm of the j-th layer and the optimum power at the radial position Rm of the reference layer, the sensitivity coefficients A to C of the optimum power between the two recording layers are calculated as follows. (Step 311). Aj = Pajm / Pa0m Bj = Pw1jm / Pw10m Cj = Pw2jm / Pw20m

Using these sensitivity coefficients, it is possible to calculate the optimum recording and erasing power for each arbitrary radius on the j-th layer (step 312). That is, the above-mentioned sensitivity coefficients A to C are integrated with the optimum powers Pa, Pw1 and Pw2 detected at each radial position of the reference layer, and the optimum powers Pawji, Pw1ji and Pw2ji at each radial position Ri of the j-th layer are calculated. calculate.

The optimum recording power at successive radial positions in the same recording layer is created by interpolation based on the optimum recording power obtained at each radial position by trial writing.
The obtained optimum recording power and erasing power for each radial position of the j-th layer are stored as a power map in the EP-ROM 7 or the like (step 313).

In this way, steps 307 to 313
By repeating the above processing for each recording layer (step 314), a power map indicating the optimum power of the track at each radial position on all the recording layers of the recording medium 1 is obtained. Then, the recording power of the light beam in the subsequent operation is controlled based on this map.

As described above, according to the present invention, a test write operation is performed for each information track at each radial position in each recording layer of the recording medium 1, and the reproduced signal is inspected.
An optimum light beam power condition for recording, erasing or reproducing information on each information track is obtained. Therefore, as compared with the related art in which the power of the light beam used for recording, erasing, or reproducing is controlled based on a power table for a single layer, that is, a single recording layer, another recording / erasing sensitivity having a different recording / erasing sensitivity is used. Recording, reproduction or erasure can be reliably performed on the recording layer.

Further, according to the present invention, the recording, erasing or reproducing conditions for a plurality of information tracks on the reference recording layer having different radial positions and the recording, erasing or reproducing conditions for the information tracks of the same radial position on different recording layers are different. The conditions for information tracks at different radial positions on different recording layers are calculated based on the sensitivity coefficient between the two obtained from the reproduction conditions. Therefore, it is possible to omit the process of selecting the recording, erasing or reproducing conditions for each information track by the test writing means, and it is possible to more quickly select the optimum recording, erasing or reproducing conditions.

In the present invention, a condition for an information track at an arbitrary radial position is calculated from recording, erasing or reproducing conditions for a plurality of information tracks at different radial positions on the same recording layer. Therefore, it is possible to omit the process of selecting the recording, erasing or reproducing conditions for each information track by the test writing means. Accordingly, it is possible to more quickly select the optimum recording, erasing or reproducing conditions.

In the above description, the physical position of the reference recording layer, that is, the reference layer, is not limited in the trial writing operation on the non-overwrite / overwrite recording medium. Recording layer may be used.

Further, an example has been described in which the optimum recording / reproducing power of the light beam is obtained as the recording condition for each of the information tracks of the land and the groove having different recording sensitivities. However, the present invention is not limited to this. For example, instead of the power, the optimum pulse width of the light beam may be obtained as the recording condition. Alternatively, the optimum reproduction power and the high frequency superimposition at the time of reproduction may be determined for each recording layer by trial reading and determined independently or by correlation.

Further, recording of each recording layer on a recording medium in advance,
It is assumed that correlation information of reproduction and erasure conditions is recorded. After performing a test write operation on one of the tracks, the recording, reproduction and erasure conditions of both tracks are set using the medium information. You may do so. In addition, the test writing operation is performed in the adjustment process of the recording / reproducing apparatus, and a part or all of each recording, reproduction, erasing condition and correlation condition with respect to the average medium characteristic of each recording layer is written in the one-time ROM in advance. You may put it.

[0101]

As described above, according to the present invention, a plurality of pieces of predetermined information are recorded on an information track on a predetermined recording layer, and a reproduction signal indicating the predetermined information is detected. A test writing means for selecting recording, erasing or reproducing conditions for an information track based on a signal is provided, and the recording, erasing or reproducing conditions for an information track on each recording layer are selected by the test writing means, and the selected condition is selected. Recording of information on an information track on an arbitrary recording layer based on recording, erasing or reproducing conditions,
This is to erase or reproduce.

Therefore, as in the prior art, recording, recording, and
Compared with the method of controlling the power of the light beam used at the time of erasing or reproducing, recording, erasing or reproducing can be surely performed on other recording layers having different recording / erasing sensitivities.

Further, the recording, erasing or reproducing conditions for a plurality of information tracks having different radial positions on a predetermined recording layer are selected by the test writing means, and the recording layer is selected based on the selected recording, erasing or reproducing conditions. The recording, erasing or reproducing conditions for the information track at an arbitrary radial position above are calculated. The test writing means selects recording, erasing or reproducing conditions for information tracks at the same radial position on two different recording layers, respectively, and a sensitivity coefficient between the two recording layers obtained from the selected recording, erasing or reproducing conditions. The recording, erasing or reproducing condition for the information track at each radial position on the other recording layer is calculated from the recording, erasing or reproducing condition for the information track at each radial position on one recording layer based on It is. Therefore, it is possible to omit the process of selecting the recording, erasing or reproducing conditions for each information track by the test writing means, and it is possible to more quickly select the optimum recording, erasing or reproducing conditions.

[Brief description of the drawings]

FIG. 1 is a block diagram of an information recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a test writing operation on a non-overwrite recording medium.

FIG. 3 is a flowchart illustrating a test writing operation on an overwrite recording medium.

FIG. 4 is a flowchart showing a test writing process for an overwrite recording medium.

FIG. 5 is an explanatory diagram showing an example of a waveform of recording power of a light beam.

FIG. 6 is an explanatory diagram showing another waveform example of the recording power of the light beam.

FIG. 7 is an explanatory diagram showing a relationship between a recording power of a light beam and a reproduction signal.

FIG. 8 is an explanatory diagram showing a relationship between an optimum recording power and a reproduction signal level.

FIG. 9 is a sequence diagram showing an operation for obtaining an optimum recording power of a non-overwrite recording medium.

FIG. 10 is a sequence diagram showing an operation for obtaining an optimum recording power of an overwrite recording medium.

FIG. 11 is a sequence diagram showing an operation for obtaining an optimum erasing power of an overwrite recording medium.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Recording medium, 1A-1C ... Recording layer, 2 ... Optical head, 2
1: light emitting element, 22: spectroscope, 24, 27: light receiving element,
25 focus actuator, 26 tracking actuator, 28 objective lens focus position sensor, 29 objective lens track position sensor, 3 signal generator, 4 AD converter, 5 ID detector, 6 controller , 7: EP-ROM, 8A to 8C: gain setting section, 10A to 10C: phase compensation section, 11: offset applying section, 12: seek / following switching section, 13: AF driver, 14: AT driver, 15: carriage driver,
16: LD power control unit, 17: LD driver, 18 ...
Reference speed generator, 19 ... In-plane / interlayer seek switching unit.

Claims (6)

[Claims] An information recording method using a disk-shaped recording medium having a plurality of recording layers and having groove-shaped information tracks provided on the respective recording layers in a circular shape or a spiral shape. An information recording / reproducing apparatus for erasing or reproducing information; test recording means for experimentally recording a plurality of pieces of information on information tracks on an arbitrary recording layer under different recording conditions; Reproduction signal detection means for detecting a reproduction signal indicating the predetermined information, and a test recording means for recording a plurality of pieces of predetermined information on information tracks on a predetermined recording layer, respectively, and reproducing the predetermined information by the reproduction signal detection means. Test writing means for detecting respective reproduction signals shown in FIG. 3 and selecting recording, erasing or reproduction conditions for the information track based on the reproduction signals. The recording means selects recording, erasing or reproducing conditions for the information track on each recording layer by the writing means, and records or erases information on the information track on an arbitrary recording layer based on the selected recording, erasing or reproducing condition. Alternatively, an information recording / reproducing apparatus comprising: a control unit for performing reproduction. 2. The information recording / reproducing apparatus according to claim 1, wherein the control means selects recording, erasing, or reproducing conditions for a plurality of information tracks having different radial positions on a predetermined recording layer by a trial writing means, An information recording / reproducing apparatus which calculates a recording, erasing or reproducing condition for an information track at an arbitrary radial position on the recording layer based on the selected recording, erasing or reproducing condition. 3. The information recording / reproducing apparatus according to claim 1, wherein the control means selects the recording, erasing or reproducing conditions for the information tracks at the same radial position on two different recording layers by trial writing means, respectively. Based on the sensitivity coefficient between the two recording layers obtained from the selected recording, erasing or reproducing condition, each radius on the other recording layer is obtained from the recording, erasing or reproducing condition for the information track at each radial position on one recording layer. An information recording / reproducing apparatus for calculating recording, erasing or reproducing conditions for an information track at a position. 4. The information recording / reproducing apparatus according to claim 1, wherein a peak value and a pulse width of a recording pulse are used as recording conditions. 5. The information recording / reproducing apparatus according to claim 1, wherein a reproducing power level and a frequency of a high frequency superimposition are used as reproducing conditions. 6. The information recording / reproducing apparatus according to claim 1, wherein an erasing power level is used as an erasing condition.